Method of and apparatus for producing paper-stock



(N0 Modem 7 3 SheetS- -Sheet 1.

S. W. ROWELL." I METHOD OF AND APPARATUS FOR PRODUCING PAPER STOCK.

Patented July 4, 1893.

LIA-NW5:

3 Sheets-Sheet 2.

(No Model.)

s. W. ROWELL.

METHOD OF AND AP N0. 500,

PARATUS FOR PRODUCING PAPER STOCK.

617. Patented July 4, 1893 Io Model.) 3 Sheets-Sheet 3.

. S. W. ROWBLL. METHOD OP AND APPARATUS FOR PRODUCING PAPER STOCK A No. 500,617. Patented July 4, 18-93 UNITED STATES PATE T OFFICE.

SIDNEY w. HOWELL, or ALBANY, NEW YORK. METHOD OF AND APPARATUS FOR Paoou'omo PAPER-STOCK.

SPECIFICATION forming part of Letters Fatent No. 500,617, dated July 4:, 1893.

Application filedMarch 3,

methods of and apparatus for producing cellulose or paper stock from wood,'jute, straw or other suitable vegetable fiber; and my improved method consists in mixing, and cansing a forced circulation, together, of the fibrous material and chemical liquor, and heating the same outside the digester during itscirculation, as willbe hereinafter described, and my apparatus comprises one or more receptacles or digesters, in which are placed the fiber materials to'be heated and the chemical liquor, together with a positive forcing means, and external heating means, whereby the whole of the said fiber material and chemicals are caused to circulate in the digester or digestcrs,

. maintain an equal temperaturethroughout.

and the fibrous materials thereby thoroughly permeated by the liquor, and cooked by means applied outside of the digester in such amanner as not to obstruct the circulation of: the mass. It also comprises certain other novel combinations and arrangements of parts as will be hereinafter fully described and specifically claimed. I i

The object of my invention 1s to produce a positive circulation of the fibrous material and chemical agents in a digester, so as to thoroughly expose every part of the fibrous material to the action of the chemicals commonly used; to heat themass externally of the digester-recoptacle or receptacles, and

the same, and thus quicken the digestive process, and reduce the material to fibers of an even and stronger quality. In this way 1 effeet a great saving in fibrous material, much of which is destroyed in otlierdigesters by the imperfect circulation of the chemical liquorin contact therewith, or by the overheating of parts of the fibrous'material while other parts remain uncooked. 'lhefibrous mate- 1892. Serial No. 423.647. memorial.)

rial often becomes crusted or discolored where it comes in contact with heated surfaces, and is thereby rendered useless, but, by my invention I obviate this difficulty, for, by the forced circulation of the fibrous material and chemicals together in a chamber or chambers offering no obstacleinternally, no part of the mass is allowed to stand upon the heated surface, but is kept in motion over the same in a manner to prevent any sticking of the'material at any point; and, as this forced circulation may be continued indefinitely, or until the fibrous materialis properly prepared ready to be discharged, a very satisfactory result can be obtained.

In the accompanying represents a side elevation of my digester in which two receptacles are employed, the heating apparatus being partly in section. Fig. 2 represents a 'top plan view of the digester shown in Fig. 1. Fig. 3 represents a side elevation of a rotary pump, which is my preferred form of forcing means. Fig. 4 represents an end view of said pump. a Fig. 5 represents a central vertical section of the pump, showing the piston thereof. Fig.6 represents a central section through a digester similar to the one shown in Fig. 1, but with the heating apparatus, placed between the two receptacles. Fig. 7 represents a top view and pardrawings, Figure 1- tial horizontal section of the digester shown central section of a digester having two receptacles and a pump placed centrally at one end of each receptacle. Fig. 10 represents a partial side elevation and section of a digester having but one receptacle so as to force the contents from one end of the digester to the other end. Fig. llrepresents a partial side elevation and section of a digester having but one receptacle, but with a partition extending nearly the entire length of same with a space below its lower end, and a pump so arranged as to circulate'the fibrous material from one compartment of the receptacle to the other; and also showing heating pipes arranged around the outside of the diand a pump arranged' in a slightly different manner.

ends, for forcing a circulation of the fibrous scroll chamber f is connected with the digester receptacle A by means of the coiled material. Fig. 15 is a horizontal section through a digester having but one receptacle, but divided by partitions into four compartments.

A A in the drawings, Figs. 1 and 2, represent two cylindrical digester receptacles provided respectively with filling caps a a at top and discharging caps 121) at bottom. These receptacles are connected at top by a circulation pipe B,and at bottom by a pump 0 having a hollow piston and a coiled pipe D, the latter being inclosed by a steam heating jacket E which has inlet and outlet pipes E E the former for connection with a live steam supply, and the latter for the escape of the waste or exhaust steam. The pumpis of the rotary type, and the hollow hub and arms of its piston c are connected by a tubular collar d with the digester receptacle A, while its circulating pipe D. The heating means, D E, are arranged outside the digester-receptacles, and thus no obstruction is offered, inside the same, to the circulation of the fibrous material mass and chemical liquor, as in apparatuses where the heating or cooking is eflected by heating means arranged partly within one or the other, or both of the reeeptacles. A heater could be constructed outside the digester receptacle by using the jacket for the mass 'to circulate through,

while a steam circulating coil is employed within the jacket for heatingthe mass of .fibrous material and chemical liquor circulating through the jacket from -one digester receptacle to the other.

'In operating with the apparatus described, the fibrous material and chemical liquors or agents are placed together in the digester receptacle A; steamis then supplied to the heating coil D, and the pump set in motion. ,The pump causes the mass, consisting of vegetable fibrous material and chemical liquor or agents, to circulate from chamberA to chamber A, and from A back to'A',and so on, until the operation is completed. During the circulation, the mass comes in contact with the heati g surface of the coiled pipe, outside of th digester-receptacle, and is thereby cooked, hile the chemical liquors or agents are, by t e circulation of the same is producedand a superior product secured. When the operation is completed the charges in the digester receptacles are discharged by blowing the same out by known methods into proper receptacles, and thereupon a fresh charge is placed in the digester.

In Figs. 6 and 7, the same construction of digester as that shown in Figs. 1 and 2 is adopted, but the steam heater isplaced vertically between the two receptacles. other respects the construction and operation are substantially the same as hereinbefore described. In Fig. 8, the pump is. shown placed inside one of the digester-receptacles at one side and nearthe bottom. In Fig. 9, the heater is not shown, but it is always contemplated to have an external heater surround the circulatory pipe, or other equivalent external heating means, combined with the circulating pipes substantially as hereinbefore described. In this view, a pump is arranged at the upper end of the digester receptacle A, and at the lower end of the digester receptacle A.

In Fig. 10, the digester has but one receptacle, a pipe 9 leading from the bottom; and a pipe 9 leading from the top of the digester receptacle and connecting with the pump, and by this construction the circulation of the mass of fibrous material and chemical liquor can be produced in a single receptacle. With this construction an external heating means will be provided, and the same may be substantially as hereinbefore described, or a In all.

coiled pipe as G in Figs. 10 and 11.be placed 7 IIO circulation beneath it from a compartment h to a compartment h. g

In Fig. 12, substantially the same construction as is shown in Fig. 11, is shown, but the pump is placed under the cylinder and the heater-is a coil as G3. In Fig. 13 two digester receptacles A A are adopted, and they are connected by a paddle wheel chamber or housing II at their tops, and, in said housing, a paddle wheel H is employed for producing the circulation. With this construction, external heating means, as in Figs. 11 and 12, will be employed, or any other suitable equivalent external heating means may be adopted.

In Fig. 14,-an elliptical digester receptacle A having'a partition I at its center is shown. At opposite sides of this partition, and at diagonally opposite positions on the digesterreceptacle, screw propellers J J are arranged on horizontal shafts J J so as to be submerged in the fibrous and chemical mass.

By revolving these propellers in opposite di-' rections, the circulation of the mass is produced, and, by reversing their movements,

. eratiou is completed.

respectively, the same results will be produced'. With this construction external heat ing or cooking means, similar to those tie scribed, will be employed.

In Fig. 15, a digester having a single cylinder or receptacle, and with it's chamber divided into four compa-rtm ents Z Z Z Z is shown. The partition m terminates below the top of the cylinder while the partitions m m terminate above the bottom of the same, as illustrated in Figs. 11 and 12; and through the partition m the pipe of a pump is passed after the manner illustrated in Fig. By this construction the pump causes the mass to circulate downward in compartment Z, under partition on then in compartment Z up over partition m, then down in compartment Z under partition m and so on until the op In connection with this construction, an externalheating means, and

apump, will be employed ashereinbefere de scribed.

What I claim as my invention is 1. In all-apparatus for producingcellulose or wood-fiber, a digeste'r consisting of one or more internally unobstructed circulation and digesting chambers, adapted to receive the fibrous material and the chemical liquor, and

provided with means tor causing a direct forced circulation together, or at the same 30 time, of both the fibrous material and the chemical liquor, and a cooking means outside the digester, substantially as and forthe purpose described.

2. The combination or" one or more directly 5 connected circulation and digesting" chambers which are unobstructed internally, a pump, circulating pipes, and an external heating or cooking coil for heating the mass while in girculatlon from the outside of the digester, 0

said mass consisting of fibrous material and the chemical liquor, and a steam chamber inclosing the coil, substantiallyas described.

3. The Within described method of mixing the chemical liquor and the fibrous material' 5 

